The present invention relates to an airbag module, and more particularly to an attachment arrangement, which supports the airbag module upon a plurality of switches while providing primary airbag module retention.
It is well known to provide an airbag module in a vehicle at such locations as in a steering wheel, a dashboard, a seat, door panel or other location. A typical airbag module includes an airbag inflator positioned adjacent an airbag to discharge an inflator gas to inflate the airbag upon sensing certain predetermined vehicle conditions.
The airbag module is commonly formed as a separate and independent unit from the vehicle. The airbag module must be easily installed yet difficult to remove by an unauthorized person. Attachment of the airbag module is further complicated by the requirement that a horn actuator be mounted to the steering wheel assembly. Typically, the horn is triggered by pressure applied to a portion of an airbag cover.
In one known arrangement, the airbag module is rigidly anchored to a base plate within a cavity formed by the molded armature of the steering wheel assembly. A thin film actuator to activate a vehicle horn is located between the airbag module and an airbag cover. Pressure applied to the airbag cover triggers the thin film actuator to selectively actuate the horn. However, mounting of the airbag module is typically with threaded fasteners, which may complicate assembly and disassembly. Further, as the thin film actuator is mounted below the airbag cover and above the airbag module, replacement of the actuator may be complicated and time intensive should the thin film actuator fail.
In another known arrangement, a switch assembly is mounted to a base plate within a cavity formed by the molded armature. The airbag module is then mounted to the switch assembly, such that pressure applied to the airbag module moves the entire module and triggers the switch to activate the horn. The switch assembly must be particularly robust to support the airbag module yet be able to restrain the airbag module during airbag actuation. Disadvantageously, the robust design of the switch assembly results in a complicated and expensive switch assembly. A driver must also apply a relatively large amount of pressure to move the airbag module and trigger the switch. This may be rather inconvenient.
Moreover, as the switch is located under the airbag module, enough clearance must be provided to allow movement of the airbag module relative to the molded armature. Commonly, this results in a noticeable separation line or gap between the airbag module and the steering wheel assembly. The separation line may be aesthetically displeasing and may allow foreign objects to find their way between the airbag module and the steering wheel assembly. The separation line may be further exaggerated by tolerance differences between the steering wheel assembly, airbag module and biasing member within the switch assembly.
Accordingly, it is desirable to provide an uncomplicated airbag mounting arrangement, which provides effective airbag module attachment. The attachment should also allow convenient horn activation with minimal pressure. It is further desirable to minimize the separation line between the airbag module and the steering wheel assembly to provide an aesthetically pleasing steering wheel assembly.
The method for installing the airbag module within the molded armature according to the present invention includes armature securing the steering wheel hub to a steering column. Switch assemblies are then mounted to the molded armature. The switch assemblies preferably xe2x80x9csnapxe2x80x9d into place.
An airbag module engagement member located at the 6 o""clock position is aligned with a corresponding armature engagement member. The airbag module is tipped toward the armature engagement member at the 6 o""clock position and a switch assembly located at the 6 o""clock position is aligned with a switch assembly receiver extending from the airbag module airbag cover. Once aligned, an operator tips the airbag module perpendicular to the steering column and presses downward on the airbag cover until each switch engagement member engages their corresponding switch assembly receivers within the airbag cover. The engagement members are also placed in their locked position at this time.
A clearance is preferably formed between each armature engagement member and each corresponding airbag module engagement member when the module is mounted to the molded armature. Thus the switch assemblies support the module.
To disassemble the module from the molded armature a flat bladed disassembly tool is receivable through a disassembly aperture on the bottom of the steering wheel assembly. The tool is inserted between the armature engagement member and the corresponding airbag module engagement member. The tool is rotated to spread the airbag module engagement member away from the armature engagement member. This is preferably repeated through two disassembly apertures. The airbag module may then be tilted away from the molded armature and further disassembled in the reverse order of assembly as described above.
The present invention therefore provides an uncomplicated yet secure airbag mounting arrangement, which provides effective airbag module attachment.
The vehicle steering wheel assembly according to the present invention includes a molded armature with outwardly extending spokes for mounting on a steering column. The molded armature receives an airbag module concealed by a cover. When a driver exerts pressure on the airbag cover, at least one of the multiple of switch assemblies activates the vehicle horn.